The SimBio Darwinian Snails lab demonstrates natural selection by showing that green crab predation drives evolution toward thicker shells when shell thickness is a heritable, variable trait. The population evolves because thin-shelled snails are eaten more frequently, allowing thick-shelled survivors to reproduce.
Darwinian Snails Lab
Study online at https://quizlet.com/_4r9kfj
1. What would happen if there were
no variability in shell-thickness?
There would not be a change in the distribution of
shell-thickness. They would all remain the same and not
evolve due to the same shell-thickness
2. What would happen if there
shell-thickness was not heritable?
the children would not have the same shell-thickness as
their parents.
3. Would the distribution of shell
thickness in the population
change over several snail genera-
tions if thickness is not heritable?
Yes. It will be random
4. If survival is not selective
(shell-thickness does not matter)
what will happen?
any snail will get eaten, bc their shells protect them equally
now
5. When mutations occur, do the chil-
dren look identical to each other
and ther parents, or are there cas-
es where one child is different?
Majority of the children are identical, but some are differ-
ent.
6. If a mutation occurred, is it
more towards thick-shelled or
thin-shelled snails or is it equally
likely to happen to either?
equally likely
7. Did individual snails ever change
their shell thickness or color?
No, the population changed over time as the thin-
ner-shalled snails got eaten. That left only the thick-
er-shalled snails to reproduce
8. What role did the predators play in
causing the population of snails to
evolve?
the predators determined which snails survived to repro-
duce
1 / 1
