How did whales, once no bigger than seals, evolve to become the largest animals on Earth? Brazilian biologist Mariana Nery...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

First sentence:

• How did whales,
  • once no bigger than seals,
  evolve to become the largest animals on Earth?

Second sentence:

• Brazilian biologist Mariana Nery believes the answer might be found in whales' DNA.

Third sentence:

• In January 2023,
• Nery and her colleagues
• [?] a study
  • showing changes over time in four whale genes associated with body size.

Understanding the Meaning

The passage starts with a question about whale evolution:

• How did whales grow from seal-sized creatures to the largest animals on Earth?

The next sentence tells us who's working on this question:

• Brazilian biologist Mariana Nery believes the answer is in whales' DNA.

Now we get to the sentence with the blank:

• "In January 2023, Nery and her colleagues _____ a study..."

Let's look at our choices:

• We're deciding between different forms of the verb "publish"
  • published (past tense)
  • publishing (participle form)
  • having published (perfect participle)
  • to publish (infinitive)

Here's what we have so far:

• "In January 2023" = a specific time in the past
• "Nery and her colleagues" = the subject (who's doing something)
• They did something with "a study"

What do we notice about the structure here?

• We have a subject ("Nery and her colleagues") that needs a main verb
  • This verb needs to tell us the main action - what they actually did
  • It needs to work with the past time marker "In January 2023"

So we need published - the simple past tense form that works as a complete main verb.

Now let's read the rest to see the complete picture:

• The sentence continues: "a study showing changes over time in four whale genes associated with body size."
• So they published a study, and that study showed specific changes in whale genes related to body size.

The complete meaning: In January 2023, Nery and her colleagues published research showing how four specific whale genes associated with body size changed over time.

GRAMMAR CONCEPT APPLIED

Main Verbs vs. Other Verb Forms

Every complete sentence needs a main verb - a verb form that can stand alone and tell you the primary action while showing when it happened (past, present, or future). Not all verb forms can do this job.

Forms that CAN work as main verbs:

• Simple tenses: published, publish, will publish
• "The team published the results." ✓

Forms that CANNOT work as main verbs alone:

• Participles (-ing forms): publishing
• "The team publishing the results." ✗ (Fragment - needs a helping verb like "is" or "was")
• Infinitives (to + verb): to publish
• "The team to publish the results." ✗ (Fragment - infinitives show purpose, not main action)
• Perfect participles (having + past participle): having published
• "The team having published the results." ✗ (Fragment - shows background action, not main action)

In this question:

• Subject: "Nery and her colleagues"
• Time marker: "In January 2023" (specific past time)
• Needed: A main verb showing completed past action
• Answer: published (simple past tense - works as complete main verb)