Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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219 views

Short-term Lamarckism in asexual single cell organisms

I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but: ...
11
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1answer
799 views

How does evolution produce complex organs

I've been wondering lately how evolution manages to produce complex organs. It is pretty obvious to me how evolution would select some minor traits like size, resistnce to illness or climate. There is ...
6
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1answer
364 views

How and when did a dedicated immune system evolve?

I have recently been doing a lot of research into the interplay between the innate and adaptive immune systems in humans, and mammalian laboratory models. This has led to my reading some interesting ...
15
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2answers
3k views

Why is glucose our primary source of energy?

Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
3
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7answers
385 views

Introductory books about evolution

This days I read some debates on evolution. That made me more interested to read something reliable on topic - I mean books. I'm christian - although I think it doesn't matter on that topic - and I ...
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2answers
164 views

Is there an “evolutionary species similarity calculator”?

Is there a website where I can input pairs of species and get an "evolutionary similarity score"? E.g. (numbers are completely made up) Input: Chimp and Human, Output: 97% Input: Cat and Human, ...
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1answer
159 views

Why would deers keep crossing a river full of crocodiles while some of them have been killed?

I recently watched a clip on Discovery Channel, where I saw deers crossing a river full of crocodiles, ignoring the fact that some of them would have been killed doing so. What could be an ...
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4answers
2k views

Why are there exactly four nucleobases in DNA?

Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
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5answers
3k views

How did the first self replicating organism come into existence?

When people try to explain evolution, they tell me that evolution is a cumulative result of mutations & natural section of the more superior individuals of a particular species. I think I'm fairly ...
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2answers
358 views

Is there any recent evidence for the aquatic ape theory of human evolution?

aquatic ape theory suggests that many features that distinguish humans from their nearest evolutionary relatives emerged because the ancestors of humans underwent a period when they were adapting to ...
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1answer
1k views

Why is the Kakapo more attracted to humans than its own kind?

The Kakapo can be seen in this video by BBC. It is said that the species is strongly sexually attracted to humans. Why could this be the case?
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1answer
283 views

Why hasn't mother nature made us aware of our lizard brain? [closed]

In many personal improvement books I've read, people make a distinction between 2 parts of our brain: the logical brain, dealing with logic, judgement, thinking; what makes Humans different than ...
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3answers
2k views

When has an organism evolved enough to be called a new species?

Imagine that we take a population of horses, split them in half and place them in completely different environments. The two species will evolve separate from each other and because the environment is ...
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3answers
1k views

Why does the butterfly have a cocoon stage in its life cycle?

Why does the butterfly have a cocoon stage in its life cycle? It could have simply grown up within the egg/cocoon, and emerged as a butterfly. Instead it is first an egg, then a worm, then a ...
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2answers
332 views

Why Didn't Evolution Cause the Human Body to become Streamlined?

If streamlining makes movement/locomotion quicker and easier, why didn't the apes evolve into life-forms that had streamlined bodies (much like fish)?
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1answer
117 views

Is extreme cladism a mainstream position in the species debate?

In the philosophy of biology it has been claimed many times that a popular position regarding the question of what species are, among biologists, is cladism. For my current purposes, the defining ...
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1answer
65 views

Features in individuals causing high population variation

As I understand it, a population with high variation is something sought after, since it makes the population better equipped to face a dynamic environment. Then, I guess features in an individual ...
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2answers
127 views

Genetic Models for Natural Selection?

My question is simple: Given that evolution is described by random genetic mutations allowing certain members of a species to gain a reproductive advantage over others that coexist in the particular ...
6
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2answers
7k views

How do archaea relate to eukaryotes and bacteria?

I've read that they all share some genes, internal structure, and behaviour with each other, but with different degrees of overlap depending of what the function is. E.g., archaea have some eukaryotic ...
6
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1answer
138 views

Alternatives to fittest-win and Moran processes as simple mathematical models of selection

When modeling selective sweeps as a micro-building block in models of macroevolution (not to be confused with misuses of this in creationist arguments), I use the fittest-win model of selection as a ...
5
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1answer
133 views

Homologies to insect wings

All winged vertebrates have wings which are homologous to each other and to the forelimbs of the non-winged vertebrates. But what about insect wings? Are all insect wings homologous, and are there any ...
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3answers
2k views

How does Artificial Selection work?

As far as I know for evolution to work mutations are necessary. Mutations are the raw material on which natural selection works. But mutations are always completely random and human beings have no ...
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1answer
283 views

What are samples of “Outlaw Genes”

I read this in a paper Keller and Ross describe their greenbeard gene as an ‘outlaw’. Admittedly, the comment is only made in passing, but are they correct? In this context an outlaw is ...
5
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1answer
592 views

How and why did mouth and nasal cavity evolve separate?

My initial objection is that nose filters air, mouth is for eating but is used for breathing also, plus they both are used to create sounds. What is the cause and reason in this case, why do we need ...
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1answer
124 views

Is there a comprehensive database of fossils (with images) online?

Not sure if this is the best stackexchange to ask... I have not been able to find a decent database of fossils on the web, does one exist? Here are some of the links I have found through Wikipedia ...
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1answer
182 views

What is the similarity between how cells organize themselves to form a human and how humans organize themselves to form a society? [closed]

Some things I have gathered. Common properties - individuals - communicate - local view - selfish - specialize - organize - replicate - cooperate - emergence Terminology cell ...
4
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1answer
63 views

Productive turnover and generations in the fruit fly

I was reading about the Lenski experiments on the evolution of E. coli bacterium and Dr. Elders's experiments on the evolution of the guppy. These two experiments absolutely fascinated me, and seemed ...
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2answers
208 views

Does becoming martyr have an evolutionary advantage?

This is related to How does "be altruist to those who are similar to you" evolve? Altruism that is Not reciprocal Not familiar has little explanation. One possible explanation is that ...
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1answer
1k views

What factors are known to affect evolution?

My understanding is that the possible mechanisms of evolution are: Environmental changes Cultural/mating preferences Population Immigration Genetic Mutation Am I missing anything? I've heard that ...
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2answers
165 views

Are there other mechanisms for mutation besides imperfect DNA replication?

I was reading http://www.askamathematician.com/2012/05/q-is-quantum-randomness-ever-large-enough-to-be-noticed/ and saw: [...] the evolution of entire species can be changed by a single mistake ...
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1answer
308 views

What animals stop other members of their species from mating and why?

(In particular primates) I know chimps do. Powerful alpha males chimp would beat up omega males that they caught mating. I know gorillas do. Powerful alpha males gorillas would beat up omega males ...
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3answers
484 views

The evolution of dogs through domestication and artificial selection

I am currently reading Richard Dawkins's book 'The Greatest Show On Earth: The proof for evolution' and in the second chapter he talks very much about the evolution of dogs. He says centuries ago ...
13
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1answer
2k views

Why do we grow so much hair on our heads compared to our bodies?

I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
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2answers
3k views

Did animals evolve from plants?

Did animals evolve from plants? Did animals' ancestors have chloroplasts in their cells?
10
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2answers
189 views

Did we first have swimming birds or flying birds?

Looking at the swimming birds building nests just across my garden, I suddenly wondered how evolution came to swimming birds and whether flying birds started swimming or whether swimming bird like ...
8
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2answers
150 views

Are there any structures in mammals that are used only by males?

There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
9
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2answers
140 views

Why is selfishness the 'obvious' strategy?

Thinking of behaviours an organism can adapt, at the very base an action can always be either selfish or altruistic (cooperative). Usually, selfish behaviour is assumed to be the preferred choice and ...
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3answers
392 views

How did the human brain evolve?

A common question posed is, "how did the eye evolve?", because the eye is so complex. However, this has been answered rather clearly and there are several examples around the world of animals in ...
11
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1answer
710 views

Is there an evolutionary advantage to crying when sad?

It seems as though the act of crying when sad does nothing to relieve that sadness. Is there an advantage to crying from an evolutionary perspective, or is it the end result of a different process? ...
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4answers
1k views

Why do men have nipples?

I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them? ...
11
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1answer
205 views

In which order did the cells of the immune system evolve?

Thinking about how complex the interactions between different types of immune system cells (T-helpers, T-Killers, Phagocytes, B-Cells etc.) are, it's fascinating how they all combine to get the ...
14
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2answers
836 views

Why is 'Grudger' an evolutionary stable strategy?

I am currently reading 'The Selfish Gene' by Richard Dawkins, which I am sure many here have read. The topic are evolutionary stable strategies (ESS) regarding cooperation. I apologise for the long ...
10
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1answer
130 views

What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?

I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage? For example, consider a ...
8
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2answers
174 views

Is there a dominant gene for right-handedness?

Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular ...
16
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1answer
453 views

How did viruses come to be?

My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any ...
11
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3answers
224 views

How do we know that dinosaurs were related to lizards and/or birds?

Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
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1answer
325 views

How To Avoid Macro-Evolution Confusion? [closed]

I regularly encounter students who believe humans came from amoebas and when asked why they often say Macro-Evolution has been scientifically proven. Macro-evolution is defined as evolution at or ...
11
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4answers
228 views

What was the reason for some plant and animals to become giant in course of evolution?

The dinosaurs, mammoths, giant plants etc are known to be bigger than modern animals. I wonder why they had been lived and why they are not living now? I really don't know much but is it something ...
13
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5answers
334 views

Can species back-evolve?

One of the tenets of Darwin's theory is the survival of the fittest, ie adaptation of features that allow a species to adapt better to its surrounding environment. I am wondering that given the right ...
9
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1answer
702 views

How does population stability evolve?

The number of individuals constituting a population is called population size. Over time population size does not remain constant, it fluctuates to different extent over generations because of ...