The document discusses issues in comparing body mass and speed, highlighting the spurious correlation between certain traits. It suggests calculating contrasts for each trait as a solution and references Brownian motion and Markov processes on trees. The findings provide insight into correcting previous misunderstandings in trait correlation.

1. Walking on a tree
Journal Club – 2014.07.24
Leo Martins

2. Problem: compare e.g. body mass (X)
with speed (Y)

3. Problem: compare e.g. body mass (X)
with speed (Y)

4. Problem: compare e.g. body mass (X)
with speed (Y)
Correlation between
traits red and yellow
is spurious
Correlation between
traits red and yellow
is significant

5. Solution: for each trait, calculate the
constrasts

6. Solution: for each trait, calculate the
constrasts
Brownian motion

7. Solution: for each trait, calculate the
constrasts
Brownian motion

8. Solution: for each trait, calculate the
constrasts
Brownian motion

9. Solution: for each trait, calculate the
constrasts
Brownian motion

10. Now we know what went wrong

11. Other Markov processes on trees

12. Other Markov processes on trees

13. Other Markov processes on trees

14. Other Markov processes on trees

15. Other Markov processes on trees