Fossil $X$ is older than fossil $Y$ if
$X$ was found deeper in sediment than $Y$
$Y$ was found deeper in sediment than $X$
$Y$ had less vestigial organs
Fossil $Y$ had a homologous and analogous organs of $X$
The Chronological order of human evolutionfrom early to the recent stages is
The hypothesis that all photosynthetic organisms require a source of hydrogen was first proposed by
Sweet potato and potato is an example of
KFD virus is a