Suppose a population of crabs in a certain tidal ecosystem thrives. These male crabs have one large claw and one small claw, but variation exists in the size of the large claw. They wave the large claw to attract females to their burrow. Females are attracted to males with larger claws. Which crabs will be more likely to have more offspring in this environment?

How does pregnancy begin? a) a placenta forms in the uterus b) a sperm reaches an egg in the fallopian tubec) the blastocyst differentiates into two cell types d) contractions begin in the uterine wallapex

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?

Which type of landform forms at the plate boundary as a result of divergent stress