What caused seed abundance to decrease from 1975 to 1978

The finch population decreased.

Explanation:

When finches eat seeds, some pieces fall onto the ground which grow up to have more seeds. The seeds that survived were too big for a finches tiny beak. Without this cycle in place, seeds had no way to reproduce.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation: