A quick question about bees and dawkins!

[andyandy]

ok

just a quickie, i remember reading in the selfish gene that worker bees and ants share 2/3 genetic material....

but i can't remember why....i can't find it on the internet, and it's annoying me...

cheers

 

[clerihew80]

Ants and bees are both part of the order Hymenoptera, along with wasps and sawflies. Ants actually evolved from prehistoric wasps.

Does this answer your question? If not, I have a copy of The Selfish Gene on hand, if you're looking for a specific passage or something.

 

[brodski]

ok

just a quickie, i remember reading in the selfish gene that worker bees and ants share 2/3 genetic material....

but i can't remember why....i can't find it on the internet, and it's annoying me...

cheers

Do you mean that worker bees share 2/3 genetic material with other worker bees, and worker ants share 2/3 genetic material with other worker ants.
or do yo mean that bees share 2/3 genetic material with ants?

 

[sphenisc]

ok

just a quickie, i remember reading in the selfish gene that worker bees and ants share 2/3 genetic material....

but i can't remember why....i can't find it on the internet, and it's annoying me...

cheers

"Haplodiploidy" may be a useful term to google.

 

[andyandy]

"Haplodiploidy" may be a useful term to google.

great - it brought up this....

All social bees, wasps and ants - which I will refer to as just bees from now on - have workers that do not go on to produce offspring, but help their sexual sisters and brothers to produce offspring. Now this altruistic behaviour does not seem to make any sense, and it did cause Charles Darwin a lot of worry, so you are in good company if it confuses you too. However we tend to think of things from a human perspective, and there are major differences between us and bees that go some way to making sense of the seemingly selfless behaviour of the workers.

Quite simply a bee worker shares 75% of her genes with her sisters. Whereas we share only 50% of our genes with out brothers or sisters. And the reason for this difference is that we are diploid animals and bees are haplodiploid animals. Confused? Well let me try to explain.

In diploid animals both the male and female have two sets of chromosomes; the female egg contains one of the two sets and the male sperm contains one of his two sets. So when fertilisation occurs the fertilised egg again contains two sets of chromosomes; half from the male and half from the female. So the average degree of relatedness between sisters and brothers is 50%.

In haplodiploid animals the male has only one set of chromosomes as he develops from an unfertilised egg, so every sperm contains the same one set of chromosomes, in other words he passes on 100% of his genes in each sperm. The female however is diploid so has two sets of chromosomes, and each egg will contain one of these two sets. As males develop from unfertilised eggs this means that sons will have 100% for their genes in common with the female, and in bees this will be the queen. But the queen passed on only half her genes to her son so she is related to him by just 50%. The workers (females) will also have received one set of the possible two of the queen's chromosomes so they will be 50% related to her, and they will also have received the one set that the males has. Now the difficult bit, the relatedness between sisters. Each sister receives one of a possible two sets of chromosomes from the queen, and these make up half her genes, so there is a 50% chance that 50% of her genes will be the same as her sister's. So that's 50% x 50% = 25%, or 1/2 x 1/2 = 1/4. Then both sisters get the same set of genes from the male as he has only one set. So half their genes are exactly the same, and if you add this half to the 25% from the queen you get a relatedness of 75%.

This means that sisters (workers) are more related to each other than they are to their mother (queen), father or even any daughters they could have. However there is one major assumption here and that is that the queen mates with only one male, and we know that this is rarely the case in honeybees, and probably not in some of the other social insects.

http://www.bumblebee.org/Haplodiploidy.htm

thanks folks

 

[casebro]

Yes but- while I got 1/2 of my genes from my mother, and 1/2 from my father, they both have nearly identical genes. Or they wouldn't both be human. Plus, the chance that my brother and I might , just by chance, get the identical genes from each egg/sperm, and be identical non-twins.

Anyway, how much do any two specimens of the same species vary? As a percent of the 50,000 genes? It's ample for variations, but certainly NOT 50%.