More stupidity in the same department
Via ScienceDaily:

More of the standard failed logic on evolution.

Diet has played a large role in explaining evolutionary changes in facial shape. The earliest human ancestors ate tough plant foods that required large jaw muscles and cheek teeth to break down, and their faces were correspondingly broad and deep, with massive muscle attachment areas.

If the skull had to adjust to match the diet, how did they survive on the tough plant diet during the millions of years needed to adjust the skull?

It would make more sense to assume that we always ate whatever we could find, and our jaws were suited for eating everything we could digest, from tough to soft.

As the environment changed to drier, less wooded conditions, especially in the last two million years, early Homo species began to routinely use tools to break down foods or cut meat. The jaws and teeth changed to meet a less demanding food source, and the face became more delicate, with a flatter countenance.

The environment didn't change. Some of us moved out of the jungle because we were restless or kicked out. After we moved out, we had to eat different stuff. We ALWAYS had the mental ability to imagine and devise tools, so it didn't take long to figure those techniques. We probably solved it in an hour or so because we were hungry. After that, the jaw didn't NEED to change. It was strong enough for nuts, so it was also usable for softer food.

Why do you assume that flatter and "more delicate" is Nature's preferred direction? We breed dogs and cats for flatter faces because we want them to look like us, but Nature doesn't have that preference. (Unless you're a Catholic who thinks we are "made in the image of God"; but then why did God want us to have big brows and jaws at first? Pre-op God transitioned to Post-op God?)

Changes in the human face may not be due only to purely mechanical factors. The human face, after all, plays an important role in social interaction, emotion, and communication. Some of these changes may be driven, in part, by social context. Our ancestors were challenged by the environment and increasingly impacted by culture and social factors. Over time, the ability to form diverse facial expressions likely enhanced nonverbal communication.

"Impacted by social and cultural factors" is true. But our refined expressive ability comes from refined muscles and cerebellar control, not from skull shape. Other mammals have refined muscular control of their ears because their ears are large and visible, thus suitable signaling devices. Our ears are flat, so we lost the muscles for ear-based gesturing.

Large, protruding brow ridges are typical of some extinct species of our own genus, Homo, like Homo erectus and the Neanderthals. What function did these structures play in adaptive changes in the face? The African great apes also have strong brow ridges, which researchers suggest help to communicate dominance or aggression.

A strong brow communicates dominance? If everyone in the species has a strong brow, it's not a SALIENT feature, so it doesn't communicate anything.

Communication is in the movable muscles, not the static and universal parts. A strong brow or large nose is likely to develop more refined muscles because it's a visible transmitter. We have refined lip muscles because the lips are the most noticeable feature in an otherwise flat and uninteresting landscape; but MOSTLY because** the lips are used for SPEECH.

Putting it another way, human lips are unique because they form the output of a CLOSED RESONATOR, which enables us to create a wide variety of vowel formants.

= = = = =

** Footnote: I wish we had a convenient word for two-way causation. It's more accurate to say that we have refined lip control AND we have speech that uses the refined lip control. Both are simultaneously necessary to accomplish the PURPOSE of communication. Neither can be the cause, because neither is useful WITHOUT the other.

Labels: Grand Blueprint

  ¶ 7:30 AM