Saturday, January 30, 2016

Are invertebrates living organisms?

This is a sequel to my earlier post:

One argument I've run across to prove that invertebrates aren't "alive" in the Biblical sense is Lev 17:11 (cf. Gen 9:4; Deut 12:23), which says the "life of the flesh is in the blood." Since invertebrates don't have hemoglobin, they aren't living creatures in the Biblical sense. But there are several problems with this line of argument:

i) To say life is linked to blood is not to say life can't be linked to something other than blood. It's an affirmation, not a denial. It's perfectly consistent with other things on which life is dependent. Indeed, creationists hardly think blood is a sufficient condition for biological life.

There's no reason to think the statement involves an intended contrast between hemoglobin and hemolymph. The context concerns sacrificial land animals (or human murder victims). It's not meant to be a universal principle.

Take a statement like "life depends on water." That doesn't mean life only depends on water. It doesn't stand in contrast to "life depends on oxygen," or "life depends on sunshine."

Likewise, it's dubious to think the Pentateuch is using "blood" in the technical sense of hemoglobin, as if the concept depends on how modern medicine defines the composition of blood. That's terribly anachronistic.

ii) This interpretation would restrict Gen 1:20-21 to the creation of aquatic vertebrates, leaving the creation of aquatic invertebrates unaccounted for. But surely this passage is meant to be an inclusive statement about the creation of organisms for whom water is their natural element. Gen 1 subdivides creation according to their native habitat: air, land, water. And young-earth-creationists, of all people, should wish to affirm that Gen 1 was meant to cover, in broad categories, the creation of natural kinds on planet earth. To omit aquatic invertebrates would be a massive lacuna.

iii) What is the function of blood? It's a vital fluid. That's why blood loss can result in death.

But for invertebrates, hemolymph is functionally equivalent to hemoglobin. Both are vital fluids, without which the respective organisms will expire. Just as life is in the hemoglobin for vertebrates, life is in the hemolymph for (some) invertebrates.


  1. Hm, if YECs wish to get a little bit more technical:

    1. For starters, we could further parse "blood." Blood is made up of much more than just hemoglobin. It's also made up of a variety of leukocytes aka white blood cells (e.g. neutrophils, monocytes), thrombocytes aka platelets, blood plasma (which is the majority of what constitutes blood), proteins like albumin, immunoglobulins aka antibodies, electrolytes (e.g. sodium, chloride), clotting factors, and so on.

    2. Why is " the blood"? I presume the main answer is because hemoglobin is the part of blood which carries oxygen (and nutrients) around the body.

    However, myoglobin, which is present in the human heart and skeletal muscles, similarly acts as an oxygen carrier. Does that mean "life" could be in myoglobin just as well as hemoglobin? Yet myoglobin isn't normally "in the blood" but rather in the muscles. Is "life" therefore "in the muscles"?

    By the way, yes, hemoglobin binds oxygen, but hemoglobin likewise binds carbon monoxide and in fact even more avidly than it binds oxygen. This is why, for instance, exposure to car exhaust or smoke from fires or gas heaters can lead to carbon monoxide poisoning.

    3. At the risk of oversimplification, hemoglobin uses iron to bind oxygen, while hemocyanin (in invertebrates like mollusks and arthropods) uses copper to bind oxygen. The main relevant difference is iron vs. copper.

    Are we therefore saying "life" is "in the blood" because vertebrates use iron whereas "life" is not "in the blood" because these invertebrates use copper? If so, why is this the relevant distinction between "life" being in the blood and "life" not being in the blood? What does iron have that copper doesn't have which makes iron "life" but copper not life, even though both can bind and transport oxygen around the creature's body?

  2. I don't suspect the particular line of YEC reasoning described in the OP can stand under technical scrutiny.

    Probably YEC-ists are guilty of overreaching somewhat in their apologetic efforts to defend the literal, historical accuracy of the OT creation account, and harmonize that account with both the OT and NT testimony that death entered the theretofore perfect creation through the entrance of sin, and subsequently the curse of the Fall.

    I'm very sympathetic, but I think there are better lines of reasoning to follow in defense of Scripture than to attempt to build a doctrinal edifice on such a shaky foundation as this via hairsplitting and lingustic gymnastics.

    Certainly blood is a powerful and evocative image. Visceral. Shocking. Everyone understands it intuitively at the most fundamental level.

    Plainly there was some type of animal sacrifice (which we would surmise was bloody) involved in God's clothing of Adam and Eve after they had fashioned their own works-righteousness garments - although it's possible He simply created animal skins ex-nihilo that seems unlikely as there was probably an object lesson here.

    Righteous Abel's blood cried out from the ground after the world's first "in cold blood" murder.

    Stubborn, hardened Pharaoh watched as the Nile was turned to blood, and in the last times yet to come - days of vengeance and the wrath of the Lamb - blood figures powerfully in the events of that great and terrible Day of the Lord.

    Obviously for Christians the scarlet thread of redemption that flows throughout the Bible is that old, old story of a fountain filled with blood (and healing) flowing from a fatally wounded Savior's side. The Lamb of God slain from the foundations of the world.

    So to me it seems practically banal for Christians to attempt to co-opt the deep, rich, and theological Biblical usage of the term "blood" (not that it doesn't also employ the term literally and physically as it obviously does) in a misguided effort to bolster an obscure and flimsy ad hoc argument.

    On the other hand although there are likely better arguments, I don't think this one is particularly damaging or harmful, and it's probably primarily reflective of an intramural debate within the church between YEC-ists and OEC-ists.