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

learn more… | top users | synonyms

8
votes
3answers
2k views

Why doesn't recombination occur in male Drosophila?

"Males do not show meiotic recombination, facilitating genetic studies." For a while I have known that this phenomenon occurs, this quote comes from the Wikipedia page on Drosophila melanogaster, ...
0
votes
2answers
46 views

DNA adaptation in human life

Does our DNA adapt by human lifetime? Or do we have the same genetic information from birth to death? I mean: What is usually called "evolution" means "natural selection" like this: ...
3
votes
0answers
21 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
2
votes
3answers
625 views

How can homosexuality evolve despite natural selection?

I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
2
votes
2answers
101 views

How did the first sexual animal come to exist? [closed]

I am more or less familiar with the evolution theory based on mutations. Now, starting with a nonsexual being, how did the first organism that reproduces sexually come to exist.
3
votes
1answer
49 views

Chromosome 2 alternate explanation - apes gaining a set of chromosomes?

I'm preparing for a debate (just between friends) on evolution (I'm in support), and one of the points I plan to bring up is the Chromosome 2 evidence. I'm now trying to predict their potential ...
5
votes
0answers
24 views

Linkage disequilibrium with $n_l$ loci $n_a$ alleles

Linkage disequilibrium $\left(D\right)$ for two bi-allelic loci is defined as: $$D=X_{11}X_{22} - X_{12}X_{21}$$ , where $X_{11}$, $X_{12}$, $X_{21}$, X$_{22}$ are the frequencies of the haplotypes ...
1
vote
1answer
21 views

Could mating/recombination be responsible for evolution of entirely novel features?

The diploid chromosomal architecture is rather interesting. For example, because of diploidy we Humans have to mate. Of course in that sense, because diploid organisms often have mate, this has led to ...
2
votes
1answer
21 views

How do beneficial features evolve in species without progressing through detrimental stages?

I'm thinking in particular of wings on birds that would - I'm guessing - have to progress through stages during which they confer no particular advantage. Or is it that all evolved features must have ...
5
votes
2answers
331 views

Why does sexual selection evolve beautiful features?

First question here. I have a very raw understanding of sexual selection: Say a group of females of a certain species "likes" some feature of a certain groups of males; by "like" I mean some ...
1
vote
0answers
27 views

How did the roar evolve from snort?

When Lions roar, or Dogs show aggression, they do that snort-roar thing. They're producing sound while inhaling. How did that come to be when all (?) other forms of sound involve exhaling? Humans do ...
2
votes
3answers
4k views

Evolutionally speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
3
votes
1answer
180 views

What is needed for a G-matrix?

I have been doing a lot of reading on quantitative genetics and the G- (and B-) matrix lately. I get the principle behind performing the analysis now but I am still not sure how to do it. I'd like to ...
4
votes
0answers
37 views

Effective population size and overlapping generations

From this book; If generations overlap, then the effective population size $N_e$ does not equal the population size $N$. I know mathematical formulations in order to find the effective population ...
2
votes
1answer
56 views

Opposite results between Blomberg's K and phylogenetic signal in Phylocom (AOT)

I've been trying to test for significant phylogenetic conservatism in some plant traits. So far I used R-package picante (Blomberg's K) and AOT in Phylocom. So far these two methods yield completely ...
1
vote
3answers
139 views

Evolution (Reductionism)

My recent post was tagged as unclear so I wanted to re frame my question. Though I am a layman, I would love to read books and find the stuff, if I get an overall picture of intelligence factor. My ...
14
votes
2answers
1k views

Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
3
votes
1answer
32 views

Effective population size when the population sizes varies from season to season

Let's think of a species which has four generations per year and which population size changes from season to season so that the population size is 100 in summer, 200 in spring, 50 in autumn and 20 in ...
2
votes
1answer
59 views

Evolution of Homo Erectus to Homo Sapiens

I just read an article on Wikipedia and noticed that some similarities between Homo Erectus and Homo Sapiens in the "Comparative table of Homo species". My question is; Is it possible to say that ...
3
votes
2answers
55 views

What is the evolutionary purpose of the topology of the human ear?

What is the evolutionary purpose of the topology of human ears? I understand why the ears may have a funnel-like shape but if the various "hills and valleys" do not amplify incoming sound, what ...
1
vote
1answer
62 views

Is Natural Selection like a Copy Editor?

I am stuck on a Homework Question. It says: Evaluate the following statement: “Natural selection works like a copy editor; it works only with what is already present in a population.” (Note: ...
9
votes
1answer
246 views

When does weak selection produce qualitatively different results from strong selection?

In evolutionary game theory, it is typical to model organisms as having a base fitness that is modified slightly by the game interaction. The ratio of the game effect versus the base fitness ...
4
votes
2answers
78 views

Evolution in fruits

So, I saw a video on YouTube that says the banana we eat today is not what a banana looked like years ago. Since the banana has been genetically modified over the years, does that qualify as ...
3
votes
2answers
77 views

Why ducklings are yellow?

Why ducklings are yellow, what the evolutionary background for this? How could it help to survive? UPDATE I agree with comment below, I did remember then that ducks are wild animals too (when I ...
4
votes
2answers
71 views

How would constantly growing nails have aided early human?

Nails grow rapidly and constantly, such that without constant artificial trimming they would reach lengths difficult to manage. How did this benefit early humans, say 200kya? Were they used like ...
1
vote
4answers
56 views

What evidence do we have to derive a rate of evolution?

When analyzing how the human species evolved and will continue to evolve over time, what evidence and tools (theory/models) do we have available to derive the rate at which this happens? Is it even ...
1
vote
2answers
50 views

Many spermatozoa, but just one ovum

Why do men produce so much spermatozoa, that will get discarded, but women, just ovulum, but it's a good one. Couldn't men produce good spermatozoa as a limited edition? Where is the evolutionary ...
7
votes
2answers
488 views

Why do humans find baby animals cute?

Why do humans find baby animals like cats, dogs, ... so cute? As these are potential competitors or even natural enemies (like e.g. tigers, leopards, ..), the protection instinct (reasonable for the ...
3
votes
1answer
137 views

Parasitism and mimicry

I was reading this article which states this: Classical Batesian mimicry, in which an undefended mimic evolves to look like a toxic model, is a parasitic relationship in which the mimic gains ...
7
votes
0answers
29 views

Beginning of the urogenital system

Are any invertebrate nephridia (proto/meta) homologous with vertebrate kidneys in the sense that embryologically they also begin together with the genital system? When did the embryologic association ...
4
votes
4answers
214 views

Biodiversity is restricted by genome combinatorics?

Me and some friends are interested in opinions for the following: Conjecture The maximum number of species must be limited by the maximum combinatorial/permutational space that can be occupied ...
4
votes
1answer
74 views

Assumptions of Hamilton's rule

Which elements of the following list are assumptions of the Hamilton's rule? Population structure (non-panmictic population) Additivity = Fitness of the heterozygote equals the mean of the ...
3
votes
0answers
32 views

Visualisation of phylogeography

I am working on phylogeography on one model species and I am a beginner. You can imagine one species that came on locality more than 5 mya (million years ago). It was a good environment, so the ...
13
votes
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 ...
7
votes
1answer
128 views

Genetic Drift: Models, assumptions and empirical observations

There two main mathematical models to describe the process of genetic drift are Moran model and Wright-Fisher model. My questions concern the assumptions of these models, the existence of other ...
2
votes
2answers
58 views

Is there any evidence of increased life expectancy for animal species?

Life expectancy for human has significantly increased during the last century or so. We all know that there are many reasons that are not linked with "evolution", but I am wondering if such change in ...
12
votes
3answers
498 views

Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
1
vote
1answer
23 views

What indices can we use to describe fitness landscapes?

We usually talk of smooth or rugged fitness landscape. Are there any (standard) indices to measure the "structure" of fitness landscapes? For example, one might consider the mean epistatic ...
0
votes
3answers
63 views

Phylogenetic tree

I want to find the conventional phylogenetic tree of human, mouse, C elegans and drosophila, without all the other organisms. Do you know where can I get it? thanks, Noga
3
votes
0answers
60 views

Model for fluctuating selection

Is there any mathematical model to predict the behaviour and long-term consequence of counter-acting selection at different time scale? For example, let's consider the bi-allelic gene $A$, with ...
6
votes
0answers
130 views

Correlation between genome size and mutation rate?

Martin Nowak in his book "Evolutionary Dynamics" talks about a given correlation between genome size and mutation rate. What correlation does exactly exist between these two concepts? Is it a ...
0
votes
0answers
29 views

comparing conventional phylogenetic tree to phylogenetic trees which are based on enzymes

I built trees (for 4 organisms: mouse, human, drosophila and C-elegans) for different enzymes family, compared them to the conventional tree, and try to explain them. how would you explain these ...
1
vote
2answers
51 views

Aren't current explanations for the evolution of human cooperation a little too reductionist?

Lately, I've become a believer in the limits of reductionist explanations especially in areas like complex systems and biology. So, without wasting any more time, I'll get to my question.. Whenever ...
3
votes
1answer
41 views

Mutation rate in viruses

Mutation rate is a phenotypic trait that evolves. The process of evolution of such kind of traits are often referred to as evolvability. I am wondering about the evolution of the mutation rates in ...
2
votes
2answers
203 views

What modern insects are not (flying OR descended from flying ancestors)?

What modern insects are not flying or descended from flying ancestors? (I read somewhere that 99% are, so of course I instantly became curious which aren't. xD ) EDIT: Sorry, I should have been ...
2
votes
2answers
304 views

Why is dimethyltryptamine (DMT) being released during death?

I'm not very well informed about all the things related to biology and the current achievements of science in this field so if I'm wrong in anything I say, please let me know. Many times I've come ...
0
votes
1answer
27 views

vestigial structure question

If a species has a vestigial anatomical structure that it no longer uses, would you expect this structure to disappear over many generations through the action of natural selection? Always, sometimes, ...
1
vote
1answer
28 views

Book on yeast reproduction, evolution and on the use of yeast as model organism

I am looking for a good book in: Yeast reproduction mating types Recombination mating type determination mechanism Yeast evolution Yeast as model organism and its use in experimental biology It ...
1
vote
1answer
64 views

Evolution, self organization and neuroscience

I have rudimentary knowledge of evolution, and biology in general, so bear with me if this question is a bit naive. Let's say we have a particular trait, like highly sensitive peripheral vision. ...
1
vote
0answers
33 views

Cambrian explosion and evolutionary arms race

I've seen many times mentioned in textbooks and popular articles that a reason of the Cambrian explosion is an 'evolutionary arms race' between predators and prey. But this isn't really a sufficient ...