In which Russell does his best to explain molecular clocks
As I mentioned above, I didn't the time to explain clocks in the detail I would ideally like – there's too much exciting science to cover, and not enough time. But I have written an explanation of how Bayesian approaches to phylogeny work, in their basic form, that you can find here:
Garwood, R.J. 2020. Patterns in Palaeontology — Deducing the tree of life. Palaeontology [online] 8(12):1-10.
If you want to know more about how they work in terms of clocks, then give me a shout, and I will happily explain!
Is adaptedness the same as fitness?
I asked you above, whether you thought that being highly adapted (showing high levels of adaptedness) was the same as fitness. I think this is a really interesting question (hence me asking).
In brief, within a given environment an adaptation – to that environment – does make an organism fitter. But being highly adapted does not always mean you will have a higher fitness. For example, think about the example I have used previously of the avocado with its giant seed. This adapted to being distributed by a megafauna that is now extinct.
While being highly adapted, because that fauna has now gone extinct, the avocado is no longer particularly fit – there is nothing out there left to spread its seeds. This is one example of how these two things can become decoupled.
I outlined in the introductory video, that this time I've changed slightly how I am delivering the course content, with the last video being delivered through, and the basis of, discussion on zoom. Shorter asynchronous elements at the expense of discussion time face to face. Any feedback you have would be very much appreciated (it's all anonymous too, FYI).
Many thanks for your thoughts.