Teleology

Teleology in the strict sense is a branch of philosophy that studies final purposes or Aristotelian "final causes" of the universe and evidence of this purpose in the world's set-up — or, to use the current-fad jargon, "design".

Teleology today often insinuates itself into a style of thinking that sees natural forces as being directed toward some sort of end-goal or purpose. Teleological assumptions provide the logical basis for creationism, as evidenced in the argument from design. Teleological approaches usually lead to pseudo-scholarly works of determinism, e.g., historical determinism, biological determinism, etc.

Teleology and evolution
Teleological thinking is deeply ingrained in culture, so even people who believe evolution is how we got here can slip into it. Beware any of the following in an evolutionary discussion, particularly if you hear them coming out of your own mouth:
 * "Highly evolved" — evolution does not have directional heights or an aim in mind. (More forgivable if what is meant is merely "highly complex", "highly specialized", "the end result of many different evolutionary pressures", or "highly changed from its initial state into its current form"; consider using those instead.)
 * "More complex lifeforms" — the genomes reached their present informational content about 600 million years ago. All changes since then have substituted new complexity for old. There is no progress or direction. "More complex" in reference to an organ or biological process is usually okay, if it's being used in a purely descriptive manner (e.g., "obviously, the human brain is more complex than that of a fruitfly, so this observation may not have applicability to human medicine").
 * "Purpose" — this word may mean something if you're very careful indeed — a functional explanation rather than a historical one (e.g. "the heart's purpose is pumping blood") — but can fail to communicate to your audience that it got this way by shit just happening.
 * "The next stage of human evolution" — problems here are the words "the" and "next". When speaking from the context of a species, there almost always is no singular "next"; there are (usually) many, assuming the species does not go completely extinct. Whatever happens to humanity will be shit just happening.
 * Anything that might imply 'guided evolution'.