39
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What would cause red-haired people to become fewer?
Let's consider a possible scenario, with a simplified assumption that red hair is a simple Mendelian recessive trait.
Let's say we have a population that is 10% red hair. Everyone with red hair lives ...
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Are mutations a source of genetic variation?
Going through the possible answers
(A) Rates tend to be very high in most populations.
This is a very unclear statement. What does "high" mean? In humans, the average mutation rate per ...
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Books on population or evolutionary genetics?
TL;DR
I'd recommend Population Genetics: A Concise Guide (Gillespie) for an introduction to population/evolutionary genetics (thanks AGS for highlighting this big miss of mine on the first version of ...
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29
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Why didn't Escobar's hippos introduced in a single event die out due to inbreeding
I think one of the important things to understand in thinking about this case is that it just hasn't been that long, generationally.
Escobar imported the hippos in the late 1980s. Hippos reach sexual ...
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Books on population or evolutionary genetics?
@Remi.b's list is excellent, but it should also include Gillespie's Population Genetics: A Concise Guide.
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Discrepancy in time for genetic differences between human and chimpanzee to accumulate
Good literature work here and good question +1! In short, your main mistake was that you based your calculations on a single site and not on the whole genome. More info below.
Genome-wide vs sites ...
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14
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Term for trait that is advantageous to a population only as long as it is rare
Frequency-dependent selection is the term you are looking for, I believe. Positive frequency-dependent selection encompasses traits that become more advantageous as they become more common. Negative ...
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Why are the genomes of Humans 99.5% the same?
In a genome that is 3 billion base pairs, a difference of 0.5% works out to a difference of 15 million bases. When a single base change can change the amino acid sequence of a protein, that can add up ...
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How can someone share 50% of their DNA with their parents yet all humans share 99.9%?
It will be clear with a simple analogy.
You are 50% related to any one of your parent
Let's say you don't have any biology books. You have two friends, Alice and Bob. They each give you a copy of ...
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9
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Did Darwin ever reach the conclusion that selection will remove variation?
After reading your question, I had a vague memory that this subject was indirectly touched upon in "On the Origin of Species", so I did some text searches (in this pdf version I found online). From ...
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How do bumblebees and hornets avoid the negative effects of inbreeding?
Queens do not generally breed with their brothers, but with males from other nests. In the life cycle of bees (and other social Hymenoptera), new queens are born late in the season along with haploid ...
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9
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What are the consequences of inbreeding?
You are right. Inbreeding strongly increases overall homozygosity which subjects inbred individuals to diseases caused by rare recessive alleles. In non-inbred individuals the chance is quite low to ...
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9
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Are mutations random?
Short answer
The claim is unclear but is essentially misleading and wrong. However, IMO, for lay people, it is a good approximation to just think that mutations are random!
Here, on Understanding ...
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8
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Effect of sex-ratio on the effective population size
The reason that an unequal sex ratio affects the effective population size is because offspring are produced by one male and one female parent, and an unequal sex ratio increases the rate at which ...
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Why didn't Escobar's hippos introduced in a single event die out due to inbreeding
They often do. You hear a lot about all of the times invasive species succeed in invading a new habitat, because there is a surviving population around for researchers to observe. There are lots of ...
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Books on population or evolutionary genetics?
I personally like the Primer on Population Biology by Wilson and Bossert. For a book that is almost 45 years old, it holds up pretty well. One of the best things about this book is that they provide ...
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Books on population or evolutionary genetics?
Not relatively short, but I'm going to repeat a recommendation I just made in another thread. Population Genetics and Microevolutionary Theory by Alan Templeton covers many of the topics listed above, ...
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How do I calculate the change in allele frequency in a haploid population under selection?
Here is my full derivation to the book example you gave, hopefully it'll help you clear up what went wrong:
You need to remember that after there is selection acting on the population, you no longer ...
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How is genetic speciation defined?
Speciation in sexually-reproducing organisms can be identified as the inability to produce viable offspring. In other words, when two suspected sub-species are not able to produce viable offspring, ...
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How is genetic speciation defined?
As you probably know, there exists many different species concepts (or definitions of species). Often, you see a separation into at least six different categories of species concepts, which are then ...
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Do mutant alleles result from mutation of the wild type?
No, not necessarily!
The terms might be confusing I agree. The most common allele (the wild type allele) might be a mutant of one other type of allele (one mutant allele) present in the population.
...
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7
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Human genetic diversity in Africa in comparison with the rest of the world
Here is a tree based on mitochondrial DNA variations in human populations.
van Oven M, Kayser M. Hum Mutat. 2009 Feb;30(2):E386-94.
Updated comprehensive phylogenetic tree of global human ...
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Why didn't Escobar's hippos introduced in a single event die out due to inbreeding
There are some references on this: Castelblanco-Martinez, 2021 is a recent one. There doesn't seem to be much doubt at least that hippopotami are thriving as an invasive species.
I didn't see ...
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Initial population when i count backwards?
Your calculations are the following. Assuming non-overlapping generations, the number of ancestors you have in the last $t$ generation is given by:
$$\sum_{i=1}^t 2^t$$
This sounds correct. But ...
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Evolution of diversity and extinction resistance
The topic you describe is very interesting and known as "species selection." Some traits exist that not only affect the reproductive success of individuals, but also affect the diversification rate of ...
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Do mutant alleles result from mutation of the wild type?
The determination of whether an allele is wild-type or mutant has to do with the frequency that it is observed within a population.
In genetics, a wild-type allele can be defined as
an allele, or ...
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Genotypes in diploid/haploid cells under mitotic/meotic cell divisions
Though broad, here I provide a summary in graphical way.
Mitosis:
.
MEIOSIS: 2 successive steps : Meiosis-1 and meiosis-2
Meiosis-1
Meiosis-2
So lets see what happens with cells given at ...
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Text Book Recommendation: Organic Evolution
Organic Evolution - Definition
'Organic evolution' was a common term. It is just rarely used today. Today, we just say 'evolution' or 'evolutionary biology' when referring to the field of study of '...
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6
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Understanding ancestry testing mathematically
I'll give here a simple, non-technical answer because I'm assuming you don't need to actually perform an analysis of ancestry.
So, detecting ancestry is a non-trivial task. Given your genome ...
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Can the apparent drop in insect population be explained by local insects evolving to avoid traps?
From your own PlosOne link comes proof that the selection pressure was very weak:
"Most locations (59%, n = 37) were sampled in only one year, 20 locations in two years, five locations in three years, ...
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