Biology

Sat Apr 02, 2016 12:00 pm

Sat Apr 02, 2016 12:03 pm

The Genetical Theory of Natural Selection
Ronald Aylmer Fisher. : http://www.openlibrary.org/det ails/geneticaltheoryo031631mbp

OXFORD PRESS 1930 | ISBN 0-19-850440-3.

Sat Apr 02, 2016 1:23 pm

Pg. 1	Pg. 2	Pg. 3	Pg. 4
Pg. 5	Pg. 6	Pg. 7	Pg. 8
Pg. 9	Pg. 10	Pg. 11

Sat Apr 02, 2016 1:35 pm

The "habitable zone" for terrestrial life

Hottest: 113°C--Pyrococcus furiosus (Vulcano Island, Italy)
Coldest: -15°C--Crypotendolithotrophs (Antarctica)
Deepest: 2 miles (land)--bacteria found in rocks underground
Most acidic: pH 0.0--unclassified organisms growing on gypsum in caves
Most basic: pH 11--Alkaliphilic bacteria
Highest radiation: 5 Mrads--Deinococcus radiodurans (ubiquitous)
Longest period in space: 6 years--Bacillus subtilis (Long Duration Exposure Facility)
Farthest: Moon--Humans, Streptococcus mitus from Surveyor III camera after
3 years unprotected on lunar surface
Longest dormancy: 20-40 million years--Bacillus revived from gut of bee in
20-40-million-year-old Dominican amber
Deepest and Highest pressure: 1200 atm--cold seep community at bottom
of Marianas Trench
Saltiest: 30%--halophilic bacteria
-
Eukaryotes in extreme environments
http://www.nhm.ac.uk/research-curation/research/projects/euk-extreme/

Fri Apr 22, 2016 9:09 pm

Απο τον Βίο των Ζώων
ΝΙΚΟΛΑΟΥ Κ.ΓΕΡΜΑΝΟΥ - 1932.

ΕΚΔΟΣΕΙΣ ΕΛΕΥΘΕΡΟΥΔΑΚΗ
χωρίς τόνους.

Απτην Εισαγωγη.
[..]Ισως ημέραν τινά, οπόταν δυνηθώμεν να εύρωμεν το μεσον της τεχνητής παρασκευής ζώντος πρωτοπλάσματος,
θα είμεθα εγγύτερον προς την λύσιν του όλου προβλήματος.[..]

Αρπακτικά η σαρκοφάγα. [θ]
Ουδεμία άλλη τάξις θηλαστικών παρουσιάζει τηλικούτον πλούτον μορφών, ως των αρπακτικών.Σχεδόν πάντα τα μεγέθη
του σώματος, απο του μετρίου μεχρι του ελαχίστου περίπου, άτινα η όλη ομοταξία παρουσιάζει, παρίστανται εν τη τάξει
ταύτη, ήτις συνενοί εν αυτή και τας διαφορώτατας μορφάς , απο του κρατερού λέοντος και της τίγρεως και της άρκτου
μεχρι της αβράς γαλής και της ικτίδος. Άπαντα δεικνυούσιν εν τη σωματική αυτών εξάρτύσει και εν τη πνευματική
ικανότητι μεγάλην αναλογίαν και ομοιομορφίαν. [..] Αι πνευματικαί ικανότητες των ζώων τούτων ευρίσκονται εν
συμφωνία προς τα σωματικάς αυτών δεξιότητας.
[..]

Felis catus Aγριογαλή ΄η Αίλουρος ο Άγριος.
[..]
Επερχομένου του λυκόφωτος άρχεται των εκδρομών αυτής προς άγραν λείας. Εφωδιασμένη δι' εξόχων αισθήσεων ,
προσεκτική και πανούργος εισέρπουσα ανεπαισθήτως και ενεδρεύουσα μεθ' υπομονής, καθίσταται λίαν επικίνδυνος
εις τα μικρά ή και μετρίου μεγέθους ζώα.
[..]

ΛΕΩΝ (Felis leo)
Απλούν βλέμμα εις το σώμα του λέοντος και εις την έκφρασιν του προσώπου αρκεί, ίνα συμφωνήση τις πληρέστατα
προς την αρχαιοτάτην γνώμην πάντων των εθνών, άτινα εγνώρισαν το ζώον, οτι ο λέων είνε ο βασιλεύς των τετραπόδων
αρπακτικών και ο κυρίαρχος μεταξύ των θηλαστικών.[..]
Ο λέων ζη μονήρης,
μόνον κατα την περίοδον του οργασμού προσέρχεται προς το θήλυ, κατοικεί δε την εαυτού περιοχήν χωρίς να έρχηται
εις έριδα χάριν τροφής μετα των άλλων του είδους του.
[..]
Εν συγκρίσει προς τα λοιπά αιλουροειδή είνε οκνηρότερος και ουδόλως αγαπά τας μακρυνάς εκδρομάς , αλλα ζητεί να
διάγη τον βίον όσον το δυνατόν ευμαρέστερον.
-
Κατα τας παρατηρησεις του Selous, προτιμά ο νοτιοαφρικανός λέων να κορέννυται εκ της λείας, ήν ο κυνηγός εφόνευσεν
, αντι να φονεύση ο ίδιος το θήραμα. Ούτω π.χ. εν τω Ανατολικώ Σουδάν παρακολουθεί απο μακράν τους νομάδας,
οπουδήποτε και αν μεταβαίνωσιν ούτοι. Συμπορεύεται μετ' αυτών εις την έρημον και επανέρχεται μετ'αυτών εις το δάσος.
Θεωρεί αυτούς ως φόρου υποτελείς υπηκόους του.
Εγγύς των χωρίων δεν έρχεται προ της τρίτης ώρας της νυκτός. "Τρίς λέγουσιν οι Άραβες, αναγγέλει δια του βρυχηθμού
την έξοδον αυτού και προτρέπει δια' αυτού πάντα τα ζώα να παραμερισώσιν εκ της οδού" Τουθ' όπερ όμως δεν είναι
ακριβές , πολλώ δε μάλλον προσέρχεται ουτος σιγηλώς και κλέπτει "ως κλέπτης εν νυκτί" "(like a thief in the night)" .Θα
προσπαθήσω δε να περιγράψω την επίθεσιν του λεοντος κατα της μάνδρας, ... []

ΤΙΓΡΗΣ (felis tigris)
Εν τη ομάδι των σαρκοφάγων θηλαστικών, των φεροντων κατα το μάλλον ή ήττον εγκαρσίως ραβδώσεις προέχει η τίγρης
, ήτις μετα τον λέοντα είνε το τελειότατον μελος της ομοιογενείας των αιλουροειδών.

ΛΕΟΠΑΡΔΑΛΙΣ , ΠΑΝΘΗΡ
Απο του Αριστοτέλους και Πλινίου ήδη υφίσταται μεταξύ των εξερευνητών διαφορά γνώμης ως προς τον συστηματικόν
καθορισμόν των παρδάλεων ...[] Εις την κυρίως λεοπάρδαλιν (Felis Pardus) αποδίδονται τα εξής χαρακτηριστικά : ολικόν
μήκος 170-200 εκστμ, Η κεφαλή είναι μεγάλη και στρογγυλή, το ρύγχος ολίγον προέχον , ο λαιμός λίαν βραχύς, το σώμα
εύρωστον , το ανάστημα εν γένει αδρόν [...] ο θεμελιώδης χρωματισμός , ών ωχρώς ερυθροκίτρινος, αμαυρούται επι των
νώτων και μεταβάλλεται προς το μέρος του λαιμού και των προσθίων του στήθους εις ανοικτώς κίτρινον ή λευκοκίτρινον,
προς δέ τα κάτω και τα έσω μέρη των σκελών εις υποκιτρίνως λευκόν. Πρόσωπον, κορυφή της κεφαλής , αυχήν και
πλευρικά μέρη της κεφαλής και του λαιμού , ώμοι , βραχίονες και πήχεις , μηροί και πρόσθιον στήθος , καλύπτονται
πυκνώς υπο κηλίδων μελαινών , πλήρων και κυκλικών. [...]
Μολονότι θηρευταί και εξερευνηταί ποιούσι διάκρισιν μεταξύ λεοπαρδάλεως και πάνθηρος, εν τούτις η διαίρεσις αυτή
δεν αναγνωρίζεται εν τω συστήματι και δεν δύναται να εφαρμοσθή καθ΄όλην την γραμμήν. Πάνθηρ και λεοπάρδαλις
είναι έν μόνον είδος (Felis Pardus) . Συνηθίζομεν οπωσδήποτε να καλώμεν το μέν αφρικανικόν είδος λεοπάρδαλιν, το δέ
ασιατικόν πάνθηρα. [...] Η λεοπάρδαλις ή πάνθηρ είναι το ωραιότατον πάντων των επι της γής αιλουροειδών. Βεβαίως
αναγνωρίζομεν εν τω λέοντι τον βασιλέα των ζώων και θεωρούμεν την τίγριν ως το επικινδυνότατον των αποτελούντων
την αγρίαν ταύτην ομάδα όντων, βεβαίως κέκτηται ο οτζελώτος περίβλημα πλουσιώτερον εις χρωματισμούς. Αλλ' ομως
ως προς την αρμονίαν της κατασκευής του σώματος, ως προς την ωραιότητα της διαγραφής του τριχώματος, ως προς την
δύναμιν και δεξιότητα , την χάριν και αβρότητα των κινήσεων υπολείπονται τα ανωτέρω ζώα και πάντα τα λοιπά
αιλουροειδή της λεοπαρδάλεως. Αν και το μέγεθος της λεοπαρδάλεως δεν είναι σημαντικόν, είνε ομως αυτή φοβερός
εχθρός πάντων των ζώων και αυτού του ανθρώπου, καίτοι αποφεύγει τούτον, όταν δύναται. Κατέχουσα τα πρωτεία της
ευκινησίας και ούσα πανουργοτέρα ετέρων αρπακτικών , γνωρίζει να εξαπατά και το ωκυποδώτατον και δειλότατον
αγριμαίον. Συναντά τις αυτήν σχεδόν τόσον συχνά επι των δέντρων όσον και κεκρυμμένην εν τινι θάμνω. Το σώμα της
ελίσσεται και στρέφεται προς πάσας τας διευθύνσεις, και ο πούς πατεί τόσον σιγηλώς, ως αν υπεβάσταζε το ελαφρότατον
σώμα. Εκάστη κάμψις ειναι κομψή, κυκλική και αβρά , συντόμως ειπείν, λεοπάρδαλις τρέχουσα ή έρπουσα αποτελέι
αληθή απόλασιν των οφθαλμών.
Φονέυει πάντα τα δημιουργήματα, άτινα δύναται να καταβάλη , αδιάφορον αν ταύτα είναι μεγάλα ή μικρά , αν αμύνωνται
ή αν ανευ αμύνης καθίσανται λέια αυτής. Αντιλόπαι, θώες και μικρά κτήνη αποτελούσι την κύριαν αυτής τροφήν. [...]
Πάν οικοδίατον ζώων είναι αρεστόν αυτή, συλλαμβάνει δε και τους κύνας, καίτοι ούτοι γενναίως αμύνονται. Όταν η
λεοπάρδαλις νομίζη οτι τα νεογνά αυτής απειλούνται , ή οταν τραυματίζηται ή προσβάλληται, ορμά λυσσαλέα κατα του
εχθρού. [...] Αι επίσημοι εκθέσεις εν Ινδίαις αναφέρουσιν, οτι κατα την τελευταίαν δεκαετίαν εφονεύθησαν υπο
λεοπαρδάλεων 2368 άνθρωποι. [...] Αιχμαλωτιζομένη η λεοπάρδαλις δεν εξοικειούται συνήθως με τον επιμελητήν της,
αλλ'εξακολουθέι διατηρούσα την αγριότητα και τας αιμοβόρους διαθέσεις, μεθ'όλας τας επιδαψιλευομένας εις αυτήν
περιποιήσεις.

-----------------
Αρπακτικά [π]
Τα αρπακτικά πτηνά ζώσι μονήρη,
συνέρχονται δε εις ζεύγη κατα την εποχή της συζεύξεως, η οποία συμπίπτει κατά την άνοιξιν.
[..] Της συζεύξεως προηγούνται παντοία παίγνια, οίον εξαίρετοι πτητικαί ασκήσεις, λίαν διάφοροι της συνήθους
πτήσεως, αληθείς χοροί εις υψηλά της ατμοσφαίρας στρώματα .. []

Χρυσαετος (aquila chrysaetus) . Oί ιδίως αετοί έχουσι το ράμφος μέγα ... [] Ο Χρυσάετος είνε ο μέγιστος και
ισχυρότατος, επίσης ο αδρότατα κατασκευασμένος , μεταξύ των συγγενών ειδών, το θηρευτικόν πτηνόν πάντων
των της Έσω Ασίας λαών, ο ήρωας των διαφόρων μύθων, το σύμβολον δε της δυνάμεως και της ρώμης.Το μήκος
αυτού είνε 85-95 εκστμ και το πλάτος των πτερύγων περι τα 2 μέτρα. Παρά τω ηυξημένω πτηνώ ο χρωματισμός
εν το συνόλω του φαίνεται σκοτεινώς καστανόχρους. το δε..[..]
Ο χρυσαετος οικέι τα υψηλά όρη και τους λίαν εκτεταμένους δρυμούς της Ευρώπης, της Ασίας και της Βορείου
Αμερικής , αποπλανάται όμως ενίοτε και μέχρι της Νοτιοανατολικής Αφρικής.Εν Ελλάδι είνε ο κοινότατος
μεταξύ των αετών, ως πτηνόν επιδημητικόν εις ολόκληρον την Ελλάδα και εις τας νήσους και νεοττεύον εις τα
υψηλά όρη. Καλείται κοινώς σταυραετός ή και απλώς αετός.
Κατοικεί κατα προτίμησιν επι των υψηλών ορέων εις τους αποκρήμνους βράχους και τας απροσίτους περιοχάς
εν γένει.
[]

Sun Jun 19, 2016 8:05 pm

Functioning ‘mechanical gears’ seen in nature for the first time

http://www.cam.ac.uk/research/news/functioning-mechanical-gears-seen-in-nature-for-the-first-time

Mon Jul 04, 2016 5:57 am

Mon Jul 04, 2016 6:02 am

Chapter III - IV :
Darwin, the descent of Man. 1871

To return to our immediate subject: the lower animals, like man,
manifestly feel pleasure and pain, happiness and misery. Happiness
is never better exhibited than by young animals, such as puppies,
kittens, lambs, &c., when playing together, like our own children.
Even insects play together, as has been described by that excellent
observer, P. Huber,* who saw ants chasing and pretending to bite
each other, like so many puppies.

We will now turn to the more intellectual emotions and faculties,
which are very important, as forming the basis for the development
of the higher mental powers. Animals manifestly enjoy excitement,
and suffer from ennui, as may be seen with dogs, and, according to
Rengger, with monkeys. All animals feel Wonder, and many exhibit
Curiosity. They sometimes suffer from this latter quality, as when the
hunter plays antics and thus attracts them; I have witnessed this with
deer, and so it is with the wary chamois, and with some kinds of
wild-ducks.
[...]
It is almost superfluous to state that animals have excellent
Memories for persons and places. A baboon at the Cape of Good Hope, as
I have been informed by Sir Andrew Smith, recognised him with joy
after an absence of nine months. I had a dog who was savage and averse
to all strangers, and I purposely tried his memory after an absence of
five years and two days. I went near the stable where he lived, and
shouted to him in my old manner; he shewed no joy, but instantly
followed me out walking, and obeyed me, exactly as if I had parted
with him only half an hour before. A train of old associations,
dormant during five years, had thus been instantaneously awakened in
his mind. Even ants, as P. Huber* has clearly shewn, recognised
their fellow-ants belonging to the same community after a separation
of four months. Animals can certainly by some means judge of the
intervals of time between recurrent events.
[...]
The Imagination is one of the highest prerogatives of man. By this
faculty he unites former images and ideas, independently of the
will, and thus creates brilliant and novel results. A poet, as Jean
Paul Richter remarks,* "who must reflect whether he shall make a
character say yes or no- to the devil with him; he is only a stupid
corpse." Dreaming gives us the best notion of this power; as Jean Paul
again says, "The dream is an involuntary art of poetry." The value
of the products of our imagination depends of course on the number,
accuracy, and clearness of our impressions, on our judgment and
taste in selecting or rejecting the involuntary combinations, and to a
certain extent on our power of voluntarily combining them. As dogs,
cats, horses, and probably all the higher animals, even birds*(2) have
vivid dreams, [..] we must admit that they possess some power of imagination.

Of all the faculties of the human mind, it will, I presume, be
admitted that Reason stands at the summit. Only a few persons now
dispute that animals possess some power of reasoning. Animals may
constantly be seen to pause, deliberate, and resolve. It is a
significant fact, that the more the habits of any particular animal
are studied by a naturalist, the more he attributes to reason and
the less to unlearnt instincts.* In future chapters we shall see
that some animals extremely low in the scale apparently display a
certain amount of reason.
[..]

It is difficult to
understand how anybody who has ever kept a dog, or seen an elephant,
can have any doubt as to an animal's power of performing the essential
processes of reasoning."
[...]

Archbishop Sumner formerly maintained* that man alone is capable
of progressive improvement. That he is capable of incomparably greater
and more rapid improvement than is any other animal, admits of no
dispute; [..] With animals, looking first to the
individual, every one who has had any experience in setting traps,
knows that young animals can he caught much more easily than old ones;
and they can be much more easily approached by an enemy. Even with
respect to old animals, it is impossible to catch many in the same
place and in the same kind of trap, or to destroy them by the same
kind of poison; yet it is improbable that all should have partaken
of the poison, and impossible that all should have been caught in a
trap. They must learn caution by seeing their brethren caught or
poisoned.
[..]

Our domestic dogs are descended from wolves and jackals,* and though
they may not have gained in cunning, and may have lost in wariness and
suspicion, yet they have progressed in certain moral qualities .
[..]

It has often been said that no animal uses any tool; but the
chimpanzee in a state of nature cracks a native fruit, somewhat like a
walnut, with a stone.* Rengger*(2) easily taught an American monkey
thus to break open hard palm-nuts; and afterwards of its own accord,
it used stones to open other kinds of nuts, as well as boxes. It
thus also removed the soft rind of fruit that had a disagreeable
flavour. Another monkey was taught to open the lid of a large box with
a stick, and afterwards it used the stick as a lever to move heavy
bodies; and I have myself seen a young orang put a stick into a
crevice, slip his hand to the other end, and use it in the proper
manner as a lever. The tamed elephants in India are well known to
break off branches of trees and use them to drive away the flies;
and this same act has been observed in an elephant in a state of
nature. In these several cases stones and sticks were employed as
implements; but they are likewise used as weapons.
[..]

Abstraction, General Conceptions, Self-consciousness, Mental
Individuality.- It would be very difficult for any one with even
much more knowledge than I possess, to determine how far animals
exhibit any traces of these high mental powers. This difficulty arises
from the impossibility of judging what passes through the mind of an
animal; But when a dog sees another dog at a
distance, it is often clear that he perceives that it is a dog in
the abstract; for when he gets nearer his whole manner suddenly
changes if the other dog be a friend. [..]

It may be freely admitted that no animal is self-conscious, if by
this term it is implied, that he reflects on such points, as whence he
comes or whither he will go, or what is life and death, and so
forth. But how can we feel sure that an old dog with an excellent
memory and some power of imagination, as shewn by his dreams, never
reflects on his past pleasures or pains in the chase? And this would
be a form of self-consciousness.
It is generally admitted, that the higher animals possess
memory, attention, association, and even some imagination and
reason. If these powers, which differ much in different animals, are
capable of improvement, there seems no great improbability in more
complex faculties, such as the higher forms of abstraction, and
self-consciousness, &c., having been evolved through the development
and combination of the simpler ones. It has been urged against the
views here maintained that it is impossible to say at what point in
the ascending scale animals become capable of abstraction, &c.; but
who can say at what age this occurs in our young children? We see at
least that such powers are developed in children by imperceptible
degrees.
[..]

That animals retain their mental individuality is unquestionable.
When my voice awakened a train of old associations in the mind of
the before-mentioned dog, he must have retained his mental
individuality, although every atom of his brain had probably undergone
change more than once during the interval of five years. [..]

Language.- This faculty has justly been considered as one of the
chief distinctions between man and the lower animals. But man, as a
highly competent judge, Archbishop Whately remarks, "is not the only
animal that can make use of language to express what is passing in his
mind, and can understand, more or less, what is so expressed by
another."* In Paraguay the Cebus azarae when excited utters at least
six distinct sounds, which excite in other monkeys similar
emotions.*(2) The movements of the features and gestures of monkeys
are understood by us, and they partly understand ours, as Rengger
and others declare. It is a more remarkable fact that the dog, since
being domesticated, has learnt to bark*(3) in at least four or five
distinct tones. Although barking is a new art, no doubt the wild
parent-species of the dog expressed their feelings by cries of various
kinds. With the domesticated dog we have the bark of eagerness, as
in the chase; that of anger, as well as growling; the yelp or howl
of despair, as when shut up; the baying at night; the bark of joy,
as when starting on a walk with his master; and the very distinct
one of demand or supplication, as when wishing for a door or window to
be opened. According to Houzeau, who paid particular attention to
the subject, the domestic fowl utters at least a dozen significant
sounds.*(4)
[..]

Several writers, more especially Prof. Max Muller,* have lately
insisted that the use of language implies the power of forming general
concepts; and that as no animals are supposed to possess this power,
an impassable barrier is formed between them and man.*(2) With respect
to animals, I have already endeavoured to shew that they have this
power, at least in a rude and incipient degree.

[..]
Belief in God- Religion.- There is no evidence that man was
aboriginally endowed with the ennobling belief in the existence of
an Omnipotent God. On the contrary there is ample evidence, derived
not from hasty travellers, but from men who have long resided with
savages, that numerous races have existed, and still exist, who have
no idea of one or more gods, and who have no words in their
languages to express such an idea.*

[..]
It is, however, impossible to decide in many cases whether certain
"social instincts" have been acquired through natural selection, or
are the indirect result of other instincts and faculties, such as
sympathy, reason, experience, and a tendency to imitation; or again,
whether they are simply the result of long-continued habit.

The social animals which stand at the bottom of the scale are guided
almost exclusively, and those which stand higher in the scale are
largely guided, by special instincts in the aid which they give to the
members of the same community; but they are likewise in part
impelled by mutual love and sympathy, assisted apparently by some
amount of reason. Although man, as just remarked, has no special
instincts to tell him how to aid his fellow-men, he still has the
impulse, and with his improved intellectual faculties would
naturally be much guided in this respect by reason and experience.
[..]

Summary of the last two Chapters.- There can be no doubt that the
difference between the mind of the lowest man and that of the
highest animal is immense.
Nevertheless the difference in mind between man and the higher
animals, great as it is, certainly is one of degree and not of kind.
We have seen that the senses and intuitions, the various emotions
and faculties, such as love, memory, attention, curiosity,
imitation, reason, &c., of which man boasts, may be found in an
incipient, or even sometimes in a well-developed condition, in the
lower animals.
If it
could be proved that certain high mental powers, such as the formation
of general concepts, self-consciousness, &c., were absolutely peculiar
to man, which seems extremely doubtful, it is not improbable that
these qualities are merely the incidental results of other
highly-advanced intellectual faculties; and these again mainly the
result of the continued use of a perfect language. At what age does
the new-born infant possess the power of abstraction, or become
self-conscious, and reflect on its own existence? We cannot answer;
nor can we answer in regard to the ascending organic scale. The
half-art, half-instinct of language still bears the stamp of its
gradual evolution. [] The ennobling belief in God is not universal with
man; ...

Fri Mar 03, 2017 12:00 pm

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ο Βίος των Ζώων

Functioning ‘mechanical gears’ seen in nature

pg77

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