The answer is biological evolution.
The theory of biological evolution explains how organisms evolved during the time. It explains how the characteristics of different species changed over generations. According to the theory, most of current species developed from some distinctly different species that have lived a long time ago.
Answer: D. Extinctions occur at higher rates during times of ecological stress when populations and species are poorly adapted.
Closed system because I used safari for 5 minutes!
Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament.