geographic isolation
Yes, most bird species' feathers are distinctly different from other birds' feathers.
biological evolution ...........studyisland
Taxonomically, they belong to the weasel family, and the 'true weasel' genus. However ermine (Mustela erminea) are a distinctly different species to the animal commonly referred to as a weasel (Mustela nirvalis).
The theory you're referring to is evolution, which suggests that species can change over time through a process of natural selection and genetic variation. This means that the diversity of life we see today could have descended from common ancestors that existed in the past.
Tortoises can vary significantly in weight depending on the species. The largest tortoise species, the Galápagos tortoise, can weigh over 400 kg (880 lbs). Other species, like the Aldabra giant tortoise, can also reach similar weights. Smaller tortoise species typically weigh much less, often ranging from 1 to 15 kg.
Number of different species
No, eggs do not undergo metamorphosis into something quite different; rather, they develop into a mature form of the same species. For instance, a bird egg will hatch into a chick, which is a young bird, and eventually grow into an adult bird. Metamorphosis, as seen in insects like butterflies, involves a complete transformation from one life stage to a distinctly different one, but this process is not applicable to all egg-laying species.
different species of plants having very different DNA causes them to be different species of plants.
different species of plants having very different DNA causes them to be different species of plants.
different species of plants having very different DNA causes them to be different species of plants.
different environments produced different species by natural selection.
different environments produced different species by natural selection.