If each level in a food chain typically loses 90 percent of the
energy it takes in, and the producer
level uses 1000 kcal of energy, how
much of that energy is left after the
third trophic level?

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.

it should be d) transitional fossils.

they show the gradualism of evolution throughout a period of time

i guess because love can be toxic ‍♂️