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

6
votes
1answer
99 views

Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = ...
1
vote
1answer
72 views

Interpretation of graph from evolutionary biology

I am studying evolutionary biology, and been presented with this graph: I am having some difficulties understand its meaning. For a start, why is time measured as a fraction of the population size? ...
1
vote
0answers
22 views

How many traits can a multivariate breeders equation handle?

The multivariate breeders equation (MBE) by Lande predicts the change in a trait $\Delta \bar z$ (response) as $\Delta \bar z = G \beta$ where $G$ is a genetic variance-covariance matrix and ...
1
vote
0answers
26 views

What do we know about the cellular structure, processes, environment, and immediate ancestors of the last universal common ancestor (LUCA)? [closed]

I am up for all scientifically sound speculations, and sources are highly welcome. I've looked into this quite a bit myself via scholar.google, the wiki article, and /r/askscience. I'm really looking ...
3
votes
0answers
62 views

Understanding the meaning of $s$ and $t$ in a population genetics equation

Sewall Wright in this article (1937) at the end of page 313 gives the equation: $$\Delta q = (s+tq)q(1-q) \space\space\space\space\space\space\space\space\space(1)$$ This equation is an ...
4
votes
2answers
449 views

Are there any multicellular forms of life which exist without consuming other forms of life in some manner?

The title is the question. If additional specificity is needed I will add clarification here. Are there any multicellular forms of life which exist without requiring the consumption (destruction) of ...
5
votes
2answers
103 views

Simulating substitution rate of neutral mutations

I am trying to computationally simulate a population based on the Wright-Fisher model I would like to get to the classic result of the neutral theory of molecular evolution that the rate of neutral ...
0
votes
1answer
43 views

Simplest Biological Organism? [duplicate]

What is the simplest biological organism from which a DNA sample has been or could be obtained? Could the resulting DNA be processed and examined in such a way that the resulting information would ...
1
vote
1answer
69 views

Evolution, What would the first plants have been like?

I am curious what the first plants are thought to have been like, what they may have evolved from, and how much earlier (or later) than animals they are thought to have moved to land, if they even ...
2
votes
0answers
44 views

Does the Jungian notion of collective unconsciousness have any legitimacy in the light of modern neurobiology and epigenetics?

Carl Jung has long ago proposed a rather controversial notion of collective unconsciousness [1, 2, 3], a form of the unconscious (that part of the mind containing memories and impulses of which ...
2
votes
0answers
47 views

What is the allelic frequency at mutation-selection-drift equilibrium?

mutation-selection equilibrium At mutation-selection equilibrium the expected frequency $f$ of a given locus is $$f ≈ \frac{\mu}{s\cdot h}$$ , where $\mu$ is the mutation rate, $s$ is the selection ...
0
votes
1answer
39 views

What's the evolutionary reason behind decussation?

A bunch of stuff in the human nervous system decussates. Optical information inputs from the eyes cross over in the optical chiasm. Multiple sensory and motor pathways cross-over before ascending the ...
1
vote
1answer
70 views

Possibility of Human cloning

Technology has evolved so much as to clone animals. But, what about human cloning? Is it really possible to create humans in lab? Or is it that technology has not advanced to that level..? Why cant ...
2
votes
2answers
109 views

are the spontaneous generation and evolution the same idea but in a different time scale?

I was in my biology class, learning the history of spontaneous generation and how this idea was discarded. I told my teacher that is the same as evolution but in a different timeline. I Argue that ...
0
votes
0answers
31 views

Calculate generations since divergence

Can the formula $\mu = k/(2t + 4Ne)$ be used to calculate the divergence time for any two species given a mutation rate, generation time and sequence divergence value?
2
votes
1answer
32 views

Somatic Mutations in meristem tissue in plants

In angiosperm, in which layer of the meristem does a new mitotic mutation occurring has chance to be found in a pollen grain or in an ovule? I also welcome some insights about non-angiosperm plants.
1
vote
0answers
20 views

Evolutionary reasoning behind redundancy of CST and RuST

According to my neuro-anatomy class, both the Corsticospinal Tract (CST) and the Rubrospinal Tract (RuST) control upper limb movement. What the evolutionary reasoning behind this redundancy and the ...
23
votes
4answers
4k views

Why don't mammals have more than 4 limbs?

Arthropods have 6 or more limbs and arthropods with 6 limbs appear to move faster than arthropods with 8 limbs so I wonder whether this might have something to do with fast and efficient locomotion. ...
9
votes
2answers
817 views

What is the evolutionary explanation for bat's echolocation [closed]

The bat's ability for echolocation is amazing (so are other the abilities of other animals). I was wondering how all of it came to be.
1
vote
1answer
45 views

Definitions of robustness and canalization

The concepts of robustness and canalization are fashionable today in the biology literature. However, I am not sure of their definitions and I am not sure either that all authors actually use the same ...
13
votes
2answers
192 views

How is menstruation not suicide in the wild?

Watch any wilderness special for more than a few minutes, and you'll notice a familiar pattern: when a predator catches the scent of blood on the wind, the hunt is on. Wounded animals make the best ...
0
votes
0answers
28 views

Why men are stronger than women? [duplicate]

Is there a possibility that human males and females used to have the same strength? That maybe it is because for a long time men have been doing the manual labour and sports and women haven't and ...
3
votes
0answers
69 views

At what rate do chromosomal rearrangements occur?

How often does chromosomal rearrangements occur? i.e. what is the rate of chromosomal rearrangements? I am interested about these kind of chromosomal rearrangements that are passed on to the ...
1
vote
0answers
31 views

How likely is it that through dog breeding, tail-wagging has been disassociated with happiness?

I am not a biologist, so sorry to anybody for misinformation in this post. If I understand correctly, dogs evolved the ability to show emotions through various sounds and tail-wagging in order to ...
2
votes
2answers
105 views

Do couples having children later in life act as an evolutionary mechanism?

Ok, this may be just wild nonsense and I have to warn that my knowledge on the subject is limited. I was reading about how in some countries people choose to have children later in life. After that ...
14
votes
2answers
2k views

How and why did mammals go back to the oceans?

If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the ...
4
votes
1answer
44 views

Definition of “structural underdominance”?

In Stathos and Fishman (2014), the authors refer to the concept of structural underdominance. The first time they mention it is in the first paragraph of the second page (left column) and the term is ...
3
votes
0answers
17 views

Evolutionary motivation behind number of neurons in DCMMP

I'm studying neuro-anatomy right now and I was surprised to learn that there are only three neurons along the Dorsal Column Medial Lemniscal Pathway (DMLP) which relays mechanical sensations from the ...
4
votes
2answers
121 views

What governs the size of animal bodies?

Million of years ago there lived dinosaurs up to 36 m high. About 10,000 years ago lived Machairodontinae -compared to cats today they were huge. About 400,000 years ago lived Mammuthus trogontherii: ...
16
votes
2answers
4k views

How many humans have been in my lineage? Is it almost the same for every human currently living?

If I were to count my father, my grandfather, my great-grandfather, and so on up till, say chimps, or the most common ancestor, or whatever that suits the more accurate answer, how many humans would ...
9
votes
3answers
141 views

Why is green fur not a thing?

In most biomes on earth, and certainly in the most densely-populated, the best camouflage color or pattern for an animal would be a variant of green, so as to blend in with the leaves and grasses of ...
4
votes
1answer
45 views

Is there an association between environmental and mutational robustness?

The robustness of a genotype is the ability of this genotype to resist (always produce the same phenotype) to various parameters such as mutations and environment. The ability of a genotype to resist ...
2
votes
0answers
19 views

Mutation-drift equilibrium and among loci variance in heterozygosity

At mutation-drift balance, the increased heterozygosity brought by new mutations is exactly equal to the loss of heterozygosity due to genetic drift. At equilibrium, the expected heterozygosity for a ...
7
votes
2answers
112 views

Why does botulinum toxin seem to be more dangerous to humans than to other mammals?

Various mammals seem to get away with eating parts of carcasses that we would prefer to not even touch, and that we assume will make us sick. Because of that, I assume botulinum toxin is more ...
1
vote
0answers
34 views

Why do spiders have a leaf at the bottom of a piece of web?

I've lately seen a lot of instances where a leaf is dangling from a piece of web coming down off a tree. What purpose/s does this serve for the spider? Is it some sort of mechanism for the spider to ...
0
votes
1answer
28 views

Regarding inherited fertility in animals

If an animal is fertile does it follow that both its parents of the same species (not necessarily the same species of the offspring)? Was it Mayer who said a fertile male and fertile female of two ...
7
votes
1answer
189 views

Fisher's Geometric Model for Dummies

Fisher's geometric model is still today one of the most important and fundamental model in evolutionary biology but it seems to me that most student in evolutionary biology don't really understand it ...
1
vote
1answer
37 views

Evolutionary support for parenting book “The happiest baby on the block”

The book by Dr Harvey Karp (MD) The Happiest Baby on the Block proposes that the duration of human gestation has evolved as a tradeoff between cranial size and development of the infant. He ...
1
vote
1answer
60 views

Can we influence evolution by teaching primates to control fire? Should we?

Most people with a strong interest in biology will have heard of Kanzi the Bonobo, the ape that has the wherewithal to collect fuel for a campfire and play pac-man. But is it conceivable to influence ...
2
votes
1answer
76 views

How closely related are two parasites Giardia intestinalis and Trichomonas vaginalis?

How closely related (from the evolutional point of view) are parasites Giardia intestinalis and Trichomonas vaginalis? Giardia genome is about 12 Mb and its major cellular proceses are rather simple. ...
5
votes
1answer
67 views

What is the “Spandrels” debate about?

In a former question, as a side question, I asked a clarification about the "Spandrels" paper. Being not a biologist, it was the first time I encoutered it. Subsequently I tried to collect some ...
1
vote
1answer
109 views

Did spiders respond to light for building webs before artificial light was invented?

I have noticed that during summer, beautiful spider colonies grow wherever a strong light is: I'm wonder whether spiders evolved to seek naturally lighted areas where they build nests (before ...
9
votes
3answers
666 views

The evolutionary process in bird wings, especially with regard to winglets

In this answer on aviation.SE a comparison is made between the shapes of airplanes wings and the shapes of birds wings. It concludes with the following remark: After all, no bird has winglets. Not ...
5
votes
1answer
36 views

Components of the concept of Developmental Noise?

Developmental noise is a concept that correspond to the amount of possible phenotypic variance of a given genotype in a given environment. Intrinsic noise (aka Cellular noise) is a component of ...
1
vote
2answers
73 views

Is the mutation rate in organisms in general consistent over the genome?

Coming from computer science with an interest in genetic programming (a process emulating evolution) I'm curious about whether the rate of mutation is homogeneous across the whole genome, or if some ...
0
votes
3answers
80 views

Conscious evolution

Does intelligence play a vital role in the evolution of an organism? In other words does an expansion of learning capacity increase the odds of evolution for the particular biological entity?
7
votes
2answers
129 views

How does Natural Selection shape Genetic Variation?

Background Importance of the additive genetic variance As stated here, the fundamental theorem of Natural Selection (NS) by Fisher says: The rate of increase in the mean fitness of any organism ...
6
votes
1answer
91 views

What does “Mutational Variance” mean?

Background The concept of mutational variance can be found in many articles including this one for example. The mutational variance of a trait number $i$ can be found in the M-matrix in position ...
10
votes
2answers
177 views

Did Darwin ever reach the conclusion that selection will remove variation?

According to simple models of selection the genetic variance in a population should be reduced by selection. (Fisher's fundamental theorem states that the rate at which a population can evolve is ...
2
votes
2answers
126 views

Is greed an evolved trait?

Thanks for looking. I am not a biologist, but I am fascinated by evolution. I was watching the news this morning and, as so often is the case, there was a news story about a corrupt politician who ...