Question

You are a biologist studying two species of lizards.

Lizard A lays eggs in large clutches of 20-50. These clutches are buried and the lizard does not return to tend them. When the young hatch, they suffer high rates of predation. The few that survive grow to adulthood.

Lizard B lays only two eggs. It tends to a nest until the young hatch and carries them on its back until they   grow large enough to fend for themselves. The survival rate for Lizard B’s offspring is nearly 100%.

A) What type of survivorship curve is demonstrated by Lizard A? Describe one advantage and one disadvantage of this reproductive strategy.

B) What type of survivorship curve is demonstrated by Lizard B? Again, describe an advantage and disadvantage of this strategy.

Answer 1

A) Lizard A shows type III survivorship curve because the survival rate of offspring is very low. The advantage of this type of reproduction is that a large number of eggs are laid at a time and the disadvantage is no parental care for the baby to grow and protection from predators.

B) Lizard B shows type I survivorship curve.The survival during young and middle ages is more and when it becomes old a sudden death happens. The advantage of this reproduction is that better parental care for child and the disadvantage is at a time the number of Offsprings produced is very less.